12 files changed, 112 insertions, 0 deletions
diff --git a/1553/CH21/EX21.1/21Ex1.sce b/1553/CH21/EX21.1/21Ex1.sce
new file mode 100644
index 000000000..629325463
--- /dev/null
+++ b/1553/CH21/EX21.1/21Ex1.sce
@@ -0,0 +1,8 @@
+//chapter 21 Ex 1
+
+clc;
+clear;
+close;
+p=68000; r=50/3; t=9/12;
+sInterest=(p*r*t)/100;
+printf("The simple interest is Rs. %d",sInterest);
diff --git a/1553/CH21/EX21.10/21Ex10.sce b/1553/CH21/EX21.10/21Ex10.sce
new file mode 100644
index 000000000..1226d24ee
--- /dev/null
+++ b/1553/CH21/EX21.10/21Ex10.sce
@@ -0,0 +1,8 @@
+//chapter 21 Ex 10
+
+clc;
+clear;
+close;
+t=3; rateHigh=2/100; amtHigh=360;
+Sum=amtHigh/(t*(1+rateHigh)-t);
+mprintf("The sum is Rs.%.0f",Sum);
diff --git a/1553/CH21/EX21.11/21Ex11.sce b/1553/CH21/EX21.11/21Ex11.sce
new file mode 100644
index 000000000..7a18ece9c
--- /dev/null
+++ b/1553/CH21/EX21.11/21Ex11.sce
@@ -0,0 +1,10 @@
+//chapter 21 Ex 11
+
+clc;
+clear;
+close;
+debt=1092; t=3; SI=12/100;
+year1=(1+SI);
+year2=(1+2*SI);
+instalment=debt/(year1+year2+1);
+mprintf("Each instalment is Rs.%.0f",instalment);
diff --git a/1553/CH21/EX21.12/21Ex12.sce b/1553/CH21/EX21.12/21Ex12.sce
new file mode 100644
index 000000000..a1f1a10be
--- /dev/null
+++ b/1553/CH21/EX21.12/21Ex12.sce
@@ -0,0 +1,9 @@
+//chapter 21 Ex 12
+
+clc;
+clear;
+close;
+Sum=1550; rate1=8/100; rate2=6/100; total=106; 
+lent1=(total-(Sum*rate2))/(rate1-rate2);
+lent2=Sum-lent1;
+mprintf("Money lent at 8 percent is Rs.%.0f and that lent at 6 pecent is Rs.%.0f",lent1,lent2);
diff --git a/1553/CH21/EX21.2/21Ex2.sce b/1553/CH21/EX21.2/21Ex2.sce
new file mode 100644
index 000000000..a0e5beaf9
--- /dev/null
+++ b/1553/CH21/EX21.2/21Ex2.sce
@@ -0,0 +1,9 @@
+//chapter 21 Ex 2
+
+clc;
+clear;
+close;
+t=(24+31+18)/365;   //time from 4th feb to 18th april
+p=3000; r=25/4;
+sInterest=(p*r*t)/100;
+printf("The simple interest is Rs. %2.2f",sInterest);
diff --git a/1553/CH21/EX21.3/21Ex3.sce b/1553/CH21/EX21.3/21Ex3.sce
new file mode 100644
index 000000000..88b2face8
--- /dev/null
+++ b/1553/CH21/EX21.3/21Ex3.sce
@@ -0,0 +1,10 @@
+//chapter 21 Ex 3
+
+clc;
+clear;
+close;
+sInterest=2502.50; 
+r=27/2; t=4;
+Sum=sInterest/(1+(r*t/100));
+
+printf("The principle amount is Rs. %d",Sum);
diff --git a/1553/CH21/EX21.4/21Ex4.sce b/1553/CH21/EX21.4/21Ex4.sce
new file mode 100644
index 000000000..1769fc98d
--- /dev/null
+++ b/1553/CH21/EX21.4/21Ex4.sce
@@ -0,0 +1,12 @@
+//chapter 21 Ex 4
+
+clc;
+clear;
+close;
+Sum=800; amount=920; t=3; rIncrease=3;
+sInterest=amount-Sum;
+rate=(sInterest*100)/(Sum*t);
+rNew=(rate+rIncrease);
+sInterestNew=(Sum*rNew*t)/100;
+aNew=Sum+sInterestNew;
+printf("The new amount is Rs. %d",aNew);
diff --git a/1553/CH21/EX21.5/21Ex5.sce b/1553/CH21/EX21.5/21Ex5.sce
new file mode 100644
index 000000000..3cf2709a4
--- /dev/null
+++ b/1553/CH21/EX21.5/21Ex5.sce
@@ -0,0 +1,9 @@
+//chapter 21 Ex 5
+
+clc;
+clear;
+close;
+TotalInterest=11400; r1=6;r2=9;r3=14;
+t1=2;t2=3;t3=4;
+Sum=TotalInterest/((r1*t1/100)+(r2*t2/100)+(r3*t3/100));
+printf("The sum borrowed is Rs. %d",Sum);
diff --git a/1553/CH21/EX21.6/21Ex6.sce b/1553/CH21/EX21.6/21Ex6.sce
new file mode 100644
index 000000000..b7f3b82d3
--- /dev/null
+++ b/1553/CH21/EX21.6/21Ex6.sce
@@ -0,0 +1,11 @@
+//chapter 21 Ex 6
+
+clc;
+clear;
+close;
+a1=1008; t1=2; a2=1164; t2=1.5;
+sInterestDiff=a2-a1;
+sInterest2=sInterestDiff*t1/t2;
+p=a1-sInterest2;
+rNew=(sInterest2/(p*t1))*100;
+printf("The new rate is %d percent",rNew);
diff --git a/1553/CH21/EX21.7/21Ex7.sce b/1553/CH21/EX21.7/21Ex7.sce
new file mode 100644
index 000000000..fc010faba
--- /dev/null
+++ b/1553/CH21/EX21.7/21Ex7.sce
@@ -0,0 +1,9 @@
+//chapter 21 Ex 7
+
+clc;
+clear;
+close;
+t=16; 
+p=100; //assuming principle=100
+rate=((100*p)/(p*t));
+mprintf("The rate percent per annum will be %.2f percent",rate);
diff --git a/1553/CH21/EX21.8/21Ex8.sce b/1553/CH21/EX21.8/21Ex8.sce
new file mode 100644
index 000000000..5965a4968
--- /dev/null
+++ b/1553/CH21/EX21.8/21Ex8.sce
@@ -0,0 +1,9 @@
+//chapter 21 Ex 8
+
+clc;
+clear;
+close;
+SI=4/9;
+rate=sqrt(SI*100);
+t=rate; //since both are numerfically equal
+mprintf("The rate is %.2f percent and the time is %.2f years",rate,t);
diff --git a/1553/CH21/EX21.9/21Ex9.sce b/1553/CH21/EX21.9/21Ex9.sce
new file mode 100644
index 000000000..bb5044c2b
--- /dev/null
+++ b/1553/CH21/EX21.9/21Ex9.sce
@@ -0,0 +1,8 @@
+//chapter 21 Ex 9
+
+clc;
+clear;
+close;
+t1=5/2; rate1=12/100; lessby=40; t2=7/2; rate2=10/100;
+Sum=lessby/((t2*rate2)-(t1*rate1));
+mprintf("The sum is Rs.%.0f",Sum);